Plexiglass Glass Cup Display

This is something fun made from Plexiglass sheet. We had a customer come to us with this giant wooden toothbrush and ask us to make a matching glass for an advertising display.

There is this whole world called the "ad specialty" industry that put people's logos on... well, anything.

What makes plastic so fun (keep in mind that the word PLASTIC means: Capable of being shaped or formed: plastic material such as clay. See Synonyms at malleable.) is that with a little heat, imagination, time, and the proper forms - you can make anything.

It's certainly tricky to take go from a flat sheet to a compound curve, bond the joint, and then mate the bottom. But then, that's the magic in plastic fabrication

Plastic Glue and Adhesive

I thought I would blog a little about plastic glue (plastic adhesives) to help sort out the mystery of using adhesives and plastics. There's really some basic element to cover first. That's whether the plastic material you want to glue or bond CAN be solvent glued.

So let's take a test and see if the plastic can be glued. There a large group of plastics that CANNOT be solvent glued. They included polyethylene, polypropylene, teflon, acetal (Delrin), and Nylon (and some other exotic plastics).
A quick test is to take a solvent like acetone (nail polish remover) or MEK (hazardous stuff) and put a little dab on the material. If it gets tacky, you can glue it. If it does nothing, you need to use mechanical fastening or adhesive tape. There is a special treatment for Teflon to allow epoxy glues to adhere (called "etched teflon").

Water jugs, plastic gas tanks, plastic water tanks (RV's) are mostly HDPE (high density polyethylene) and can only be hot air welded. They are generally white in color. They are "waxy" and slick on the surface. Your 1 gallon milk container is HDPE. The bottome of your snowboard or ski is UHMW and cannot be solvent glued. Soda bottles are made of PETG which is difficult to solvent bond.

PVC (normally gray in color) CAN be solvent glued. PVC is used in sprinkler pipes (along with ABS). And PVC comes in CLEAR - think vinyl windows, think synthetic leather and upholstery.

Here's a list of adhesives by material type to explain further about the plastics that CAN be solvent glued... keep in mind that a "water thin" solvent adhesive needs the pieces to fit together perfectly and has a short working time - whereas a "bodied" adhesive allows some gaps to be filled and has a longer working time. ALL ADHESIVES REQUIRE 24 HOURS TO CURE AND ARE STRONGER IN 48 HOURS. Some adhesives have a 20-30 minute setting time and seem strong enough to move. They are not. I always tell people to wait overnight before testing the bond. The first 24 hours usually cures to about 85% of ultimate bond strength. The next 24 hours goes to about 90% with a couple more days to full strength. Just thought you might want to know.

Repairing a Crack in Plexiglass? Click on this link - I wrote about that elsewhere in this blog. (Repairing Plexiglass acrylic sheet and Lexan Polycarbonate sheet are similar issues)

Plastic Adhesive and Glue Cross-Reference Guide (thanks to IPS for this chart)



Plexiglass Glue - Plexiglas is an acrylic based sheet - the actual solvent for Plexiglass is Acetone, but is not a good glue as it evaporates too quickly. The proper glues are either based on a Methylene Chloride solvent formula (WeldOn 3, 4, and 16) or have PMMA monomer in the mix (WeldOn 40). I have seen people mix in other chemicals such as Acetic Acid to "enhance" it. My recommendation is learn to use what's in the can as adding other chemicals that are pretty nasty, and potentially cancerous, isn't the wise course of action. When building a display case you would use Weld-On #4 - that gives you the clear bonded edges. When building a large aquarium of 3/4" thick plexiglas you would use Weld On #40. #40 requires experience as it is a 2-part adhesive and 30 minute working time. It is almost as strong as the sheet itself.

ABS Plastic Glue - ABS is a styrene based plastic - very widely used in automotive and electronics industries. Could have a textured finish or not. Test with acetone to see if it gets tacky. ABS is a high impact material but can still crack and break. There are water thin solvents and milky bodied adhesives. Since ABS is always a solid color, it's easy to work with.

PVC Vinyl Glue - PVC could be a medium gray color or clear. It can be rigid or flexible. It could even be a foam sheet (hard or soft). Confused? Hmmm. The gray is easy. The clear is easy. But foam? Yes - sign makers use a foamed PVC sheet (called Sintra, Celtec, Komatex, etc) that is widely available and comes in white, black and a rainbow of colors. Backpackers use a soft PVC foam sheet to sleep on. Sign Banners are typically PVC based material. Convertible windows, air matresses, inflatable pool toys are mostly flexible PVC based. There are water thin and bodied glues. As in other materials, the water thin are great for matching parts. For everything else, a bodied adhesive is required.


Multipurpose Glue - I call this group of adhesives the "sticky" ones - they tend to STICK the plastics together rather than chemically solvent weld. A contact adhesive like IPS 1829 will stick 2 flat faces of materials together rather well. A "structural" adhesive like IPS WeldOn #10 is a 2 part mix - and the adhesive itself becomes structure. It's white so it's usually used behind the material where it's hidden. WeldOn #40 is also a structural adhesive and is CLEAR. It seamlessly bonds Plexiglass and is great for bonding different plastics together. #40 requires some patience learning how to mix and apply. As always, try a test part before going forward with the real deal.

Lexan Polycarbonate Glue - Polycarbonate is a bit more sensitive to solvent adhesives, so a fast drying glue like Weld On #3 is a great choice. There is a new specialty adhesive, IPS #55, that requires a special application gun. For industrial users, this baby delivers a high strength liquid that is superior to all the other glues available.


Styrene Glue - styrenes are very sensitive to solvent adhesives. Most of the styrene product that is being solvent glued is a solid color (not clear) and either is a quick shot for tight fitting parts, or you need the bodied adhesive for filling gaps (or extra working time).

Polyethylene Adhesives & Glue - The fact is that the group of olefins (polyethylene based plastics), which include LDPE, HDPE, and UHMW, are so chemical resistant that modern science has not invented a solvent glue to bond these plastics. Of course, such properties are why these plastics exist and perform their job so well. You might even note that the solvent applicators and most chemical containers are made from polyethylenes.

All is not lost - You do have some choices!

1. Mechanical fasteners - screws, nuts and bolts and the like - you may have to recess the hole or deeper countersink based on the application.

2. Pressure Sensitive Adhesive applied to 1 surface. For the thinner sheets of UHMW - called "Slick Strips" - you can peel and stick a variety of thicknesses and widths from .010" to .125" thick,

3. Contact Adhesives - IPS Weld On adhesive #1829 - it STICKS but the bond is limited as it would be with ALL solvent based contact adhesives. There are a wide variety of solvent based contact adhesives available nationwide.

4. Double Sided Tape - OK, I know you didn't want to hear this, but for some of you, laying down a few strips may do the job. There are 2 kinds of tape. Double Sided Foam Tape is a permanent adhesive good for non-smooth surfaces. "Killer Red Tape" is a thin 0.015" thick acrylic adhesive transfer tape perfect for SMOOTH surface applications. Thicker tape is available such as the line of 3M VHB tape.

5. Hot Air Welding - the way LDPE and HDPE tanks and trays are built is by hot air welding the pieces together. Similar to metal welding, but at lower temperatures, a welding rod is melted into the sheet joint to make a strong bond. The materials must be the same - you cannot effectively join dis-similar materials.

Whew. Ok - I will probably have to keep expanding this post - it's a BIG subject area.

Another Day in Plastics Fabrication at the Shop

I was walking around the shop today and saw some incredibly different tasks going on. I guess it's what makes it fun every day for me, as well as for our team. Don't forget to click on the pictures to see larger versions!

Starting at the Shipping Department, it looks like a lot of display frames are ready to ship to a regional bank. Still needs some pallet wrap and protection.

Waiting for pickup from a local museum in San Diego, I found a stack of 24" x 24" x 24" acrylic vitrines - these are made from Optix brand acrylic sheet from Plaskolite.


Over in the CNC area they are cutting out some interesting shapes for a new customer. These parts will be "line-bent" into a new shape - a lot like oragami - that will have 3-D structure. Can't tell what it is. Heck - I don't know what it is anyway. (Have to check the work order tomorrow.....)




Over in the plexiglass thermo-forming department, Jason is working on a prototype for a couple of pedestals and windows. The soft felt-like material allows him to handle the plexiglass while it is still hot (275F) without transferring any mark-off to the sheet surface.

So this base is 3" thick clear CAST Plexiglass sheet about 18" x 24". It will become a base for some art object - each object has a different shape at the base and will require tailoring of the recessed holes to make them fit. We haven't polished out the holes completely as this is a work in progress.

Check out this photo. You are looking THROUGH the center of the plexi. That's a nickel on the other side, and the bottom of this base acts like a mirror - you are seeing a reflection of the machine and ceiling!

That's crazy.












Hope you enjoyed these pix.

Architectural Resin Panels

I am sure you have noticed that in many restaurants, bars, and offices there has appeared a new kind of plastic decorative sheeting - filled with patterns and organic materials as well as solid colors. Some of these materials are made with PETG (pop bottle material) both pre and post-consumer based material (virgin and recycled resins). Some others are made from acrylics (Plexiglas). The variety and the applications seem to be endless.

We have been working with theses manufacturers for several years and do a lot of cutting, machining, and forming of these panels to help the interior designers and architects visions become reality.



At the "W" Hotel here in San Diego, we had a chance to create 1" thick panels of 3-Form Chroma material 48"x96" and then engineer the mounting holes and specialized slots for the surfboard fins that are mounted on the panels. The material was given an "aged" look - which we all thought was funny because Plexiglas does NOT yellow - but it looks cool on the wall as you can see in the picture.

Some clients use the materials as Donor Recognition boards - and we CNC cut out the boards to fit the particular look and feel of the installation.


Something new on the market are Architectural Resin Panels from Chrysalis HD - made here in California (hooray) and bringing a new set of patterns and standards to the market. The team behind this product are very creative and driven with backgrounds in design and architecture. The price is substantially less than other similar materials on the market (hooray hooray) which makes it very attractive considering the economic times. Lower price - better product is always welcome.

One of the things we like about the Chrysalis HD line is the formability of the product as most of the interior materials will allow forming (unlike many of the organic materials found in the other manufacturer's sheets). Lead time on getting this material is quick. Distributors should have stock but if they don't, sheets can be manufactured quickly. At my company we offer a "cut sheet" program to allow for designers to achieve their dreams without having to buy the whole sheet.

These are just a few of the 50+ patterns available. Cool!

Plastic Ice - Plexiglass acrylic Ice sheet

Plastic Ice. Fake Ice. Faux Ice. Artificial Ice. It is funny how there are so many things that we make that are fake. Really! I mean in Japan you walk down the street and every lunch restaurant has a set of fake portions set out to tempt you in. Even the mannequins in the department stores are looking more realistic.

Seems like everyone wants fake ice. The bigger the better. We have all kinds of fake ice in our store, but the largest block is about 9"x9". Not big enough for some people.

Today one of our suppliers came in with a sheet of fake ice. Really good fake ice. Check it out - it's crystal clear and we can cut shapes from it, or build it into pedestals or big blocks or cubes.

This sheet comes in any thickness - but I want to have sheets of 1/2" and 1" thick for some amazing possibilities.

Surfboard Donor Board in Plexiglass

The California Surf Museum was recently renovated - completely. It's located in Oceanside, just a short paddle up the coast from our facility. Being a life-long surfer, I whothey called on me to help out with the donor recognition boards. I was honored.

So I met with the architect who supplied small pieces of glass tile that were part of the color theme. We matched these tiles to a PMS color chart we use in creating custom colored plexiglass sheet. This chart is rather magical as it allows for solid, transparent, translucent, and frosted sheets. Wow.

We decided to go with a blue tint with a frosted surface on 1 side. Oh - did I say how BIG they wanted these to be? 8ft tall. It required 3/4" thick material to make the boards stiff enough. Check this picture out. The public rarely sees the gasket used in manufacturing the sheets - but asked for it to be left on to maximize the available material that was cast for the project.

Next, we had to create a surfboard shape that was a blend of the old 60's longboard and an all-around "fun board" shape. I stopped shaping surfboards in 1975, but I have been designing skateboards my whole life (and continue to produce and sell a line of, yes, fiberglass plastic skateboards and clear skateboards too). So I was honored to create these donor boards.

Here's the machines cutting out the shapes.

As soon as I get a great photo of the boards installed at the museum, I will add that.

Plexiglass Acrylic Chuppah Mandap Mundap Gazebo on the Beach

OK - we have made some interesting things to go in interesting places. When one of our event planner customers based in San Jose del Cabo asked us to build an acrylic Mundap (or Mandap) or acrylic CHUPPA for Jewish wedding ceremonies.... we said "How Big do you want it?"

They said "Oh - maybe 8 ft high and 10ft wide" and "we want the top struts to be open, so we can put fresh flowers in" and a few other requests.

And a few more requests.... make sure YOU click on these pictures for a full size view of these clear Plexiglass gazebos. (I use the term gazebo loosely of course)

We said "You realize that not only do we have to build this, but we have to ship this 1200 miles to you - without breaking - and you have to be able to assemble and disassemble this many times!" And with our "When Others Can't - We Can" attitude, we figured out the "how" and put this together. It breaks down into 8 pcs and has adjustable sliders for assembly on uneven ground.

Nice. A bit of Jewish tradition : The wedding ceremony takes place under the chuppah (canopy), a symbol of the home that the new couple will build together. It is open on all sides, just as Abraham and Sarah had their tent open all sides to welcome people in unconditional hospitality. I think that's pretty cool.

Update June 2009: here's a link to the company that makes these Acrylic Plexiglass Chuppa Mandaps.

Formed Plexiglass Wall for Koi Pond

This is one of those fun jobs we get to do every now and then. A customer who is re-landscaping the backyard decided he wanted some clear Plexiglass walls to see the water and the koi fish. For a really BIG pond. So we had to take a couple of 48x96 sheets of Plexiglas that were 2" thick and bend them into an arc about 15ft across. Then we needed to put a hand rail on top. Make sure you Click to Enlarge this picture.

There are a lot of challenges to fabricating this part. First of all, there is no 16ft long sheet, and if there was, there are not too many 16ft long ovens to heat it up! So the fabrication method is to form 2 pc, and then chemically bond the 2 sections with liquid acrylic resin. That bond is almost as strong as the sheet itself.

Cutting the toprail is another challenge as the customer wanted one continuous piece. Again, we cut 2 pc and bonded together and then to the "wall". It takes a lot of practice to use this adhesive and achieve bubble free bonds - which give the appearance of 1 continuous piece.

But wait - now that we have created this 16ft monster, how do we get this out the door and in the backyard of the customer? Even though the destination was 30 miles away, packing for transport was intricate: we had to completely support the entire piece underneath - and put this on a custom pallet. At the job site it took 8 people to carefully lift and place it in the final position.

Pretty cool! Make sure you Click to Enlarge this picture.

Corrugated and Flat Fiberlass Sheet Panels

Corrugated Fiberglass Sheets and Panels are cool. They are clear or colorful. They remind me of the 50's, yet designers are still calling out for them in modern applications from skylights, fences, wall partitions, to patio covers. Fiberglass is relatively cheap, chemical resistant, hold up to sunlight, has a great R-value, is strong and easy to cut.

There are over 500 profiles of corrugation made over the past 50 years. (I happen to have access to most of these older profiles, but you'll need 8000sf to crank up the machines). In the 21st century, only a handful are still being produced. Most of what you see as a consumer is what's called "2-1/2" corrugation. There are wood filler strips to match a cross section and strips for the ends - even aluminum nails to batten down the panels. There are several other options that I will discuss - from "R" panels, to metal building products, to something we call "Tred-Safe" - a corrugated roofing panel you can walk on.

Flat and Corrugated Fiberglass panels are rated by their "weight per square foot". The material is made from polyester resin, chopped fiberglass fibers, and sometimes acrylic modifiers are added for clarity and longevity in the sun - say for greenhouse applications. These panels are made by basically pouring the resin onto a conveyor, sprinkling the chopped fibers over the resin, and then laying a top sheet of mylar material over it. (Ok - that was really simplistic, but you get the idea) The trick is to sprinkle enough fibers on the sheet to hold it together. The more fibers, the higher the weight per square foot. At 6 or 8 ounce, it's thicker than a credit card.


Thing is, most of the panels in the big box stores are so thin they'll break before you get them on your patio cover. What a waste. Gives them a bad name. You have to go to a plastic supply center to find the good stuff. I have also seen some quality hardware chains carry them, and some specialty lumber yards offer them. You should be asking for "6 ounce" or higher. The cheapie panels are about 3 ounce. Maybe less. They typically run 26" wide (so you can overlap) x 96" long. The better 6 ounce and 8 ounce sheets come longer - 144" and more - but the shipping gets crazy on the 192" long sheets - so size does matter.

Now - for you industrial types it gets far more interesting. There are panels are DURABLE - and some so thick you can walk on them, with specific corrugations for metal building sides and skylight panels. There are "R-panels" and cooling tower panels. The sheets are typically wider - from 36" to 52" wide and thicker 8 ounce type material. But wait - there's more! You can only sprinkle so much fiber on the sheet - to go beyond the 8 ounce, you have to add fiberglass cloth and rovings! And yes. like the picture shows, you can walk on it - carefully. That's about 12 ounce material in the picture.

Fiberglass sheets and panels last a long time. There used to be a plant here in town that was made with corrugated panels. After about 40 years, the panels were still performing - even though they looked weathered. Panels 6 ounce and up usually have a warranty of 20 years - pro rated of course. I know of a customer that called about the warranty on his panels. We went out, got on the roof, and sure enough, the panels needed replacing. When asked when they were purchased, he said "Oh, I think about 35 years ago" to which we said - "Well, I guess you got 15 bonus years for free!"

Which makes me think that Fiberglass Sheets - whether corrugated or flat - will play a BIG part in helping us develop better application for solar heating of water and spaces.

Note: Fiberglass Liner Panels - for walls and ceilings - are on a future blog (yet to be written).
Note: Fiberglass sheet - structural sheet and high pressure
laminated NEMA G10 and FR4 - are on a future blog (yet to be written).

re: fiberglass sheets, panels, sheet, corrugated fiberglass panels, tube, roof panels, rod, tubing, sheeting, reinforced panels, flat, roofing, clear, pipe, greenhouse, angle, wall panels, liner panels

Plexiglass (Plexiglas) vs Glass

Thanks to my friends at Evonik Industries,
aka DeGussa, Cyro, makers of Plexiglas® brand acrylic everywhere but the USA where Plexiglass is known as ACRYLITE® acrylic sheet....

You ask: Why should I use ACRYLITE® acrylic sheet in place of standard glass?

Unsurpassed beauty, warmth and elegance! Creative design flexibility!
Caring Performance! There are so many compelling reasons to use ACRYLITE® acrylic sheet in place of glass.

Glass is tried and true - it has been around for hundreds of years. Using glass has made it possible to bring the warmth of daylight into our homes and buildings while keeping the bitterness of weather outside. We owe much thanks to this hard working material.

While properties like transparency, stiffness, and strength have helped to make glass successful, it has been limited by other properties. Its brittleness and heavy weight as well as the difficulty of cutting, shaping, coloring, and decorating glass have imposed limitations on designers, builder and architects, alike. Fortunately, there is an alternative - acrylic sheet. Acrylic is much tougher than glass, at half the weight, is easy to fabricate and form into a variety of shapes, comes in hundreds of colors and is readily decorated. It provides a new level of flexibility and allows ideas to take shape. It sets designers free!

Why use ACRYLITE acrylic sheet in place of glass?

Because acrylic sheet offers a number of significant advantages:

Performance! Acrylic is often used where safety and ease of handling are concerns. It is many times more impact resistant than conventional plate glass and has similar impact strength compared to tempered glass. If it does break, acrylic sheet will usually crack or fracture into large pieces
with edges that are much less sharp than those of broken glass. In addition to its excellent impact strength, acrylic sheet of the same size and thickness is half the weight of glass. High impact strength and light weight make acrylic sheet the choice of people who care! (personally, I am scared of glass and have several scars to prove it)

Impact and Weight: Acrylic vs. Glass

Plexiglass is HALF the weight of glass!
Plexiglass is up to 17 times more impact resistant than glass!
(use the figure of 1.5lb per SF for 1/4" thick Plexiglas.

Warmth! Acrylic feels warm to the touch, not cold like glass, because it is a better heat insulator. Compared to glass it has a lower coefficient of thermal conductivity.

Typical values for the Coefficient of Thermal Conductivity
Acrylic: 1.3 BTU/(hr-ft2)(F/inch)
Glass: 5.3 BTU/(hr-ft2)(F/inch)

Beauty and Elegance! Acrylic has crystal clarity, pure water-white edges and unmatched light transmission. The dull grey or green edges of glass cannot match the
sparkle and elegance of acrylic. Unlike glass, colorless acrylic sheet has essentially zero absorption of visible light.


Creative Design Flexibility! ACRYLITE acrylic sheet is available in a nearly unlimited array of standard, custom and designer colors. Smooth and etched surface finishes can be combined with eye grabbing colors to produce thousands of unique and exotic looks. CYRO Industries can custom match almost any color in ACRYLITE® GP acrylic sheet when modest minimum order quantities are met.

Acrylic can be cold formed into modest radii or thermoformed into flowing curves and shapes. Acrylic's excellent thermoforming properties will help ideas take shape.

Custom sizes and unusual shapes need not be a concern. Acrylic sheet is readily cut, routed or machined into intricate shapes and sizes using typical woodworking equipment. CYRO Industries can provide expert advice on appropriate blades, tooling and procedures to insure success.

Acrylic is easily decorated. It can be painted, engraved, or hot stamped.

There is no need to accept the limits of glass, with acrylic, ideas are set free!!

Where can acrylic be used in place of glass?

Acrylic is used in hundreds of different applications. Some of the more common applications where acrylic is used in place of glass are listed
below along with the benefits of acrylic.

Architectural Glazing:
* thermoformability
* easy cut to size
* impact strength
* low thermal conductivity

Fixtures, Displays and Furniture:
* sparkling water white edges
* unlimited color
* fabrication ease
* decorating
* impact strength
* light weight

Framing:
* impact strength
* conservation grades (UV Filtering)
* non-glare grades
* reduced breakage in shipping

Transportation Glazing:
* light weight
* impact strength
* thermoformability
* color availability

Stadium and Wind Break Fence Glazing:
* light weight
* impact strength
* crystal clarity
* easy cut to size

Are there other considerations when replacing glass with acrylic? The properties of acrylic are different than glass. This leads to its exceptional impact strength and lightweight, for instance. However, in some situations these differences may require design changes or even make acrylic substitution infeasible. The checklist below highlights some important considerations when
substituting acrylic for glass. CYRO's Technical Service Department can also provide assistance.

* Mechanical strength and stiffness.

Acrylic has lower tensile strength and stiffness than glass. When used in glazing, the requires thickness will usually be 1.5 - 2.5 times greater than that required for plate glass to withstand the same wind loads. When used for shelving the required thickness to support the same weight will beat least 2.5 times greater than that required for plate glass; however acrylic will offer much greater impact strength. CYRO's TechnicalService Department can provide design assistance.

* Expansion and contraction allowances.

Acrylic expands and contracts more than glass due to temperature and humidity changes. Its coefficient of thermal expansion is about 8 times greater than that of glass. Proper allowances must be made to permit expansion and contraction. CYRO's Technical Service Department can provide assistance.

* Scratching.

The surface of acrylic is not as hard as that of glass. Therefore, it is more prone to scratching and abrasion. If resistance to scratching and abrasion is important, then specify ACRYLITE® AR Abrasion Resistant sheet.This revolutionary acrylic sheet has a "glass-like" coating on one or both surfaces that resists scratching.

* Chemical Resistance.

Acrylic is not as chemically resistant as glass. Many glass cleaners cannot be used to clean acrylic sheet. If this is a concern, then specify ACRYLITE® AR
Abrasion Resistant Sheet. This revolutionary acrylic sheet has a "glass-like" coating on one or both surfaces that resists many
chemicals. Standard glass cleaners can be used to clean the coated surfaces of ACRYLITE AR acrylic sheet.

* Flammability.

Acrylic is a combustible thermoplastic. Be sure to consider all applicable building code regulations before substituting acrylic for glass.

* Codes and Regulations.

CYRO's ACRYLITE acrylic sheet products have been tested for compliance with many codes and regulations. A few of these are listed below. Exact compliance may vary
with product type and thickness. Check with CYRO's Technical Service Department for details

BOCA Evaluation Services., Research Report #96-75
SBCCI PST & ESI Evaluation Report #95112B
ICBO Evaluation Services, Inc., Evaluation Report #3715 - CC2
Classifications
* City of Los Angeles, Research Report #RR 24392
* NY City MEA #144-80-M or 145-80-M
* Wisconsin Material Approval Report #950043-L
* ANSI Z 97.1 for Safety Glazing Materials used in Buildings
* Federal Motor Vehicle Standard 2-5, Safety Glazing (FMVSS205)
* ANSI Z26.1, AS-4, 5, 6 & 7 for Safety Glazing Material for
Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land and Highway
* Federal Motor Vehicle Standard 302 for Flammability of Interior Materials
* Underwriters Laboratories Recognized Component, File #E54671
* Underwriters Laboratories Flammability Rating: 94HB in all thicknesses
* ACRYLITE GP 1.25" sheet is UL listed (UL752) as a Bullet Resistant Glazing Material, Level 1

Plastic Thermal Expansion & Contraction

So, today I spent some quality time at a potential customer's factory. They would like to replace some plastic and metal panels with higher performing plastic sheet material. They have a great business and a line of great products that are designed to be used on pickup trucks. You can imagine that the temperature extremes the product encounters are extreme - potentially from -50F to well over 130F (surface temp of the plastic could be 175F).

Everything that exists has a "coefficient of thermal expansion". Materials like glass have a very low rate - metals have a larger rate - and plastics have many different rates.

The application is a 3 ply laminate of plastic, metal, and EPS foam. All three materials expand and contract at different rates. That said, over the length of the pickup truck bed, which can be 8ft, materials can grow and shrink from 1/8" to 1/4". The fact is, even a change of 1/32" can deform a panel in a frame.

It looks like from initial discussion that a thermoset plastic, such as FRP, or fiberglass reinforced plastic, will not only reduce the amount of movement, but offer a higher impact resistance and make for a heavier duty product.

The point is: when you are using Plastics in an environment with large temperature swings, you will have a plastic part that will grow, and shrink, with the the temperature changes. Some typical coefficients of thermal expansion can be found on www.eplastics.com and a cool chart to figure this at www.ridoutplastics.com. You can see that Plexiglas move about 10 times more than glass. For a list of a range of materials, check this link.

Plexiglass sheets - sheet sizes to please everyone

Plexiglass (Plexiglas) comes in a wide variety of sheet sizes. Like a lot of materials, when you purchase the REAL stuff - there is a difference. Forget everything you saw at the big box home stores. You know, the film masked stuff jammed in a few slots in between the fence posts and bags of cement. Oh - you need it cut?

Plexiglas sheet (and other brands) are made from a machine that is over 8ft wide. They can run any length (until they run out of room) as a sheet. You can also get a ROLL of Plexiglas in certain thicknesses (not for the casual user). But the fact is: you can get Clear Plexiglass sheet in 4x8, 5x8, 6x8, 4x10, 4x12, 6x10 and so forth. Keep in mind - you might need several people to pick the sheet up! But a quality Plexiglas Distributor should have this available AND be able to trim the sheet to the final size you need.

Big is not always better - these really large sheets have specific applications. And the shipping cost to bring it to you is pricey - not every truck on the road can handle the largest sheets.

Most people will find the 48"x96" and 72"x96" sheet sizes to give the best yields for cutting. But if your company has an odd size and needs a LOT of them (say 2000 lbs or more), you qualify for custom run to size programs to eliminate waste. Pretty cool.

What about thickness? Is it really metric? Yes. While the width and length are in INCHES, the thickness is actually made in MILLIMETERS. Here's a little cross reference:

Inches mm fraction
0.060 1.5 1/16
0.080 2.0
0.118 3.0 1/8
0.177 4.5 3/16
0.220 5.5 1/4 (what you find as 1/4" at most shops)
0.236 6.0 1/4
0.354 9.0 3/8
0.472 12.0 1/2
0.708 18.0 3/4
0.940 25.0 1.0"